I went to the Olympic Park several times and there was always a long queue out the door and staff saying it was 10 minutes+ just to get in. I'm not queuing out the door for a McDonald's, biggest in the world or not.

but the queue was out the door, up the ramp and out in the main pathway. Thought fuck that and walked (though my lazy friend hopped onto one of those buggies and got a lift most of the way) to the other on the other side of the stadium and walked straight in.